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Image Resolution

Dimensions and PPI (Pixels Per Inch) determine the file size and image quality (resolution) of a digital image.

As of 2020: Take as large an image as is necessary. Derivatives of the correct resolution can be created for EMu.

  • less than 500 pixels wide/high (and less than 150 ppi) are considered low-resolution images. Images with this combination of dimensions & PPI will also have a small file-size. They are most often used for digital displays (e.g. web pages, presentations etc). Size: approx. 500 x700 pixels; approx 100 - 200 KB range for JPG-format files.
  • 500-2000 pixels wide/high (and 150-300 ppi) are considered medium-resolution images typically used for print that does not require high detail such as desktop publishing, newsprint, reports. The file size can be large, and they are not generally used for digital display. Size: ~30 MB
  • 2000+ pixels wide/high (and 300+ ppi) are high-resolution images. They are preferable for printing large media. Size: 100-200 MB

Scale

If possible, include a scale bar in any images that you take. This can be as simple as a printed ruler bar whose measurements you have checked.

File Size

In EMu, the file on the main Multimedia tab should be under 200MB in size. This applies for all archived media, including image, audio, video, 3D, and other resource types. Larger files should be stored on the Supplementary tab, with a <200MB proxy or preview media file on the main Multimedia tab.

Color

The number of bits used to create the colors or grayscales of an image. This affects the file size and resolution of the image. The more bits used the larger the file size and the higher the resolution of the image. Try to include a color bar in at least the first few images that you take in any photographing session. The X-Rite ColorChecker is similar to the ones used by staff photographers and conservationists.

  • 8-bit greyscale uses many shades of gray to produce and image.
  • 24-bit RGB (8-bits * 3 color-channels) uses the Red-Green-Blue color descriptions generally used by computers and in desktop publishing.
  • 32-bit CMYK (8-bits * 4 color-channels) uses the Cyan-Magenta-Yellow-Black color descriptions generally used in printing.

File Types & Formats

Details about standard FMNH file types & formats are here.

For images:

  • JPEG (Joint Photographic Experts Group) files use a compression method that enables fast loading of the images. This is the PREFERRED EMu image format for digital displays.
  • DO NOT upload RAW files to EMu. Convert them to TIFFs for working, and then to DNGs for archiving as supplementary files in EMu. Contact the Technology department for information about storing and archiving large high-resolution files.

File Names

Keep them short. Don't use special characters. Follow the file naming convention relevant to your area/project here.

  • If the image is of a specimen you can include the catalogue number as the first element -- e.g. FMNH1234_dorsal_view.jpg
  • If the image doesn't show a specimen, but relates to a museum project, include its Event irn as the first element, following DAMS naming conventions -- e.g. 1234_group_portrait.jpg
  • If you use Photo archives images include their Reference ID separated by an underscore, not a hyphen.

EMu Multimedia Module Fields

The following fields are mandatory:

  • Title: Name of the object in the digital file to be attached. If the asset is to be made publicly available this should be short and descriptive.
  • Description: This should include what the asset is, information on view, etc.
  • Copyright: By default all multimedia records are (c) Field Museum (Rights irn 36). As of April 2015 any web quality jpeg multimedia record attached to a Field Museum catalogue record will be given a CC-0 release.
  • Department

The following fields are advisable:

  • Other Numbers/Other Number Source: Use these fields to record the catalogue number(s); photo archives id; Project codes.
  • Subject/Keywords: This is for general themes, categories and EMu website keywords. It should not for taxonomic names.
  • Creator: Used to on combination with the copyright field. Only necessary where copyright does NOT reside with the Field Museum attach a parties record here and set the Role field to "Creator". Otherwise consider using the Other Contributor field.

DAMS and EMu Help Documentation

A brief intro to "What is DAMu?" and How to Document Media in EMu)

A brief intro to "What is DNG?"

I. How to prepare images before they're cataloged:

  1. TIFF archival color settings (8-bit color depth with embedded sRGB or AdobeRGB color profile)

  2. How to convert TIFFs to DNGs:

  3. RECOMMENDED: How to validate your DNGs after conversion

    If you'd like to set up your department's/lab's/project's workstations with Lightroom & Photoshop presets that follow the two steps above, please contact IT.

II. How to Catalog Multimedia in EMu:

III. How to retrieve media from the DAMS:

  • How to open DNGs (and convert to TIF):
    • with Adobe Lightroom
    • with Adobe Photoshop
    • with Adobe Bridge
    • For a super-simple option, try this DNG converter (Note: Adobe Photoshop--and ImageMagick/Gimp/dcraw--can convert DNGs to TIFs, but not as easily as Lightroom. If you can't use Lightroom for the conversion, contact IT for help.)

IV. Other help with DAMS:

Information about "Audiovisual Core" (ratified metadata standard for biodiversity multimedia), and EMu Multimedia fields related to it.

Status and information about the GDI DAMs implementation project.

Other Resources